What indicates that a land does not need surface drainage?

Surface drainage is essential for managing water runoff and preventing waterlogging in agricultural fields. Generally, a slope in the landscape promotes the movement of water away from a given area, reducing the need for additional drainage systems.

In the context of this question, a land with more than a 2% slope is typically well-drained because the gravitational pull allows water to flow away from the soil surface effectively. With adequate slope, the natural topography aids in the drainage process, which means that excess water will not accumulate, thus negating the need for surface drainage interventions.

On the contrary, land that is flat or has a gentle slope, such as those with less than 2% slope, may experience pooling of water, leading to saturated soil conditions that could require surface drainage systems for effective management.